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 fully covered by structured data. The description adds useful context about what the record contains (costs, provider, reliability metrics), which is informative. It doesn't describe response size, pagination, or failure behavior, but for a single-record fetch with read-only annotations, this is acceptable.

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, tight sentence that front-loads the verb and resource, then lists what the payload contains. Zero waste, every clause 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?

For a single-id fetch with readOnlyHint=true, openWorldHint=false, 1 fully-described parameter, and no output schema, the description adequately conveys purpose, the data returned, and the id source. It's reasonably complete. A higher score would need explicit 'use with search first' guidance, but the tool's simplicity means the description is close to sufficient.

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 coverage is 100% — the single 'id' parameter is fully described as 'capability id/slug from search'. The description adds that the id is a 'slug' and its provenance ('from search'), which slightly supplements the schema but doesn't change the baseline. With one fully-documented parameter, a 3 is appropriate.

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?

Clear verb+resource: 'Fetch the full record for one MeshMarket capability by its id (slug)'. It distinguishes from sibling 'search' (which finds caps) and 'mesh_discover' (which likely lists/browses). The description names the tool's specific scope (one record by id) and conveys content (what it does, costs, provider, reliability).

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 tells the user when this applies: retrieving a fuller record for a capability previously found by search. It implicitly distinguishes from 'search' (which returns lighter results) by saying 'full record'. However, it doesn't explicitly say 'use search first to get an id, then fetch', or state exclusions/alternatives by name.

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