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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely new context: that it performs no install or connection to the listed service, and that it mirrors a specific read endpoint. It does not discuss pagination or caching, which is a minor gap given a single-slug lookup.

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 short sentences, front-loaded with the action and contents, then the endpoint mapping, then the exclusion. No filler. Slightly episodic, but every sentence contributes.

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 read-only, single-parameter lookup with no output schema, the description is nearly sufficient: it says what is returned and that no external side effect occurs. Missing only the note about how to obtain a valid slug, which the sibling search_tools presumably supplies.

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 0% for the single 'slug' parameter, so the description carries the burden. Showing 'GET /api/v1/tools/{slug}' implicitly identifies the parameter's role and implies it identifies a tool listing, but no naming convention or lookup guidance is given; the schema's pattern and maxLength do the rest.

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?

Specific verb ('Read') plus resource ('a tool listing') with the content enumerated: product facts, setup, billing, limitations, sources. It also gives the exact REST equivalent, which pins down semantics. It stops short of explicitly contrasting with the closest siblings (search_tools, get_provider), so it does not fully earn a 5.

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?

Usage is implied by the REST-path equivalence and by 'Read a tool listing', and the negative clause 'Does not install or connect to the listed service' usefully bounds expectations. However, there is no explicit when-to-use-vs-alternative guidance (e.g., use search_tools to find a slug first, use get_provider for vendor-level data).

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