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

Annotations already declare readOnlyHint, idempotentHint, and closed-world scope, so the safety profile is covered. The description adds the useful behavioural fact that the result is the authoritative coverage set, which is what makes it worth calling for validation or disambiguation. It says nothing about result size or ordering, a minor gap given annotations carry the rest.

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 what the tool returns, then when to use it, then when not to. No wasted phrasing and the exclusion comes last where it reads naturally.

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-optional-param, read-only enumeration with no output schema, the agent has everything needed to call it and interpret it as a coverage check. Only the shape/volume of the returned list is undocumented, which is a small omission rather than a blocker.

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% and the single optional 'search' parameter is fully documented as a case-insensitive brand/model filter in the schema itself. The description contributes no additional parameter guidance, so 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+resource ('Every grinder BrewMark supports') with explicit scope — the full supported catalogue, not a search result set. It is immediately distinguishable from find_grinder and get_grinder_chart, which take a name or produce a chart rather than enumerating coverage.

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?

Gives two concrete use cases (checking coverage, disambiguating multi-match results) and an explicit when-not clause: it is not needed just to look up a name because the other tools accept ordinary names directly. That is a clear routing rule against named siblings.

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