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

The annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavioral context by disclosing that the response includes the /go/<slug> outbound link, which the agent would otherwise not know. It does not describe the rest of the returned record or error behavior for a missing slug.

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?

A single sentence with zero filler, front-loading the verb, cardinality, and keying parameter. Nothing is repeated from the name or title, and no clause could be removed without losing 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?

For a one-parameter read-only lookup with no output schema, the description covers what it returns (a catalog tool plus the outbound link) and how it is keyed. Minor gaps remain around the shape of the returned record and failure on an unknown slug, but the essentials for correct invocation are present.

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% and the schema already gives slug examples (eodhd, sam-gov-opportunities). The description only restates that the slug identifies a catalog tool, adding no format, normalization, or matching semantics beyond the schema. 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?

The description states a specific verb and resource: 'Return one catalog tool by its slug.' The word 'one' implicitly contrasts with the list/search siblings, so an agent can tell this is a single-item lookup. It stops short of naming an alternative explicitly, so a 4 rather than 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 only implied: 'by its slug' signals this is the tool to call when the slug is already known, while list_categories and search_tools cover discovery. There is no explicit when-to-use or when-not-to-use statement, and no mention of what happens with an unknown slug.

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