mcp.tc directory

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds genuine behavioral context: setup output 'always uses the vendor's own URL or package' (a trust/sourcing guarantee) and that it surfaces changes detected by mcp.tc's periodic checks plus owner edits. It stops short of noting rate limits or freshness/pagination of those change checks.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The key scope statement is front-loaded in the first clause, and the two flowing sentences are dense rather than padded. The exhaustive enumeration of ten client names is the one stretch that costs length without adding decision-relevant information, since the schema already lists them.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple two-parameter read tool with annotations and an output schema, the description is complete enough to call correctly. Most of its length re-describes return values that the output schema already covers, which is slightly redundant, but nothing an agent needs is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so both parameters are already fully documented, including the client enum. The description adds marginal value by naming all ten client targets, reinforcing what the 'client' parameter selects, but it introduces no syntax or format detail beyond the schema. Baseline 3 for a schema-documented tool.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Opens with a specific verb+resource ('Everything about one listing'), then enumerates exactly what that means: description, tools, sign-in, endpoint/install command, setup steps, recent changes. The scoping phrase 'one listing' inherently distinguishes it from the sibling search_servers and list_categories without needing to name them.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description is entirely about what the tool returns; it never states when to call it versus search_servers, nor prerequisites such as needing a slug obtained from a prior search. The only usage hint (slug comes 'from search_servers') lives in the schema, not the description. An agent must infer the workflow.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is fully covered without the description. The description adds the return shape (slugs + counts) and a cross-tool linkage, but offers nothing else the annotations don't already establish.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences with zero filler; the content description is front-loaded and the usage hint follows tightly. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return values needn't be explained, and annotations carry the safety profile. The description is nearly complete for a simple no-arg list tool, missing only explicit guidance on when this lookup precedes search_servers.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters and the schema coverage is trivially complete, so the baseline of 4 applies. The description's instruction about the slug is about another tool's argument, not this one's, so it adds no parameter meaning here.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description identifies a specific resource (the directory's categories) and what each entry carries (slugs and server counts), which clearly separates it from get_server and search_servers. The verb is only implied ("List" comes from the name/title), but the scope is unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

"Pass a slug as the category of search_servers" implies the downstream workflow this tool feeds, which is useful. However, it never states when to call this tool versus search_servers directly, nor any prerequisite for the flow, leaving usage to inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds real behavioral value beyond them: compact results, featured-first then most-viewed ordering, and the returned fields (slug and mcp.tc link).

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, zero waste, and the core purpose is front-loaded ahead of the sibling handoff and the no-args case. Each sentence carries distinct information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Despite an output schema existing, the description still summarizes result shape and ordering, and it covers the empty-argument case and the follow-up tool. Nothing needed to invoke or chain this tool is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all four parameters including the enums and limit bounds are fully documented in the schema. The description only gestures at the same axes ('keyword, category or how they connect') without adding format or syntax beyond what the schema already provides, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('Search the mcp.tc directory of MCP servers') and qualifies the search axes (keyword, category, connection type). It is immediately distinguishable from get_server (detail lookup) and list_categories.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly routes the agent onward: 'Call get_server with a slug for the endpoint URL, install command and setup steps,' and explains the no-argument behavior. It gives clear usage context but does not say when to prefer list_categories instead.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.