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

Annotations already declare readOnly, idempotent, non-destructive and open-world behaviour, so the safety profile needs no restating. The description adds context annotations cannot: that the payload includes unsupported operations, units and a data version, plus the caveat that missing data is not proof of absence — a genuine interpretive constraint for the agent.

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 sentences, no filler, with the action and its scope front-loaded and the interpretive caveat placed last where it functions as a closing rule. Every clause carries 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?

With an output schema present and rich annotations, the description only needs to say what the tool is for and when to reach for it, which it does. A slightly clearer statement that it is the entry-point discovery call for an otherwise unknown catalogue would close the remaining gap.

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?

There are zero parameters, so the baseline applies; nothing about argument semantics needs explaining. The description does not waste space discussing inputs, which is correct 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 verb 'Inspect' is paired with a concrete list of what is reported: catalogue coverage, output JSON schemas, data version, units and unsupported operations. That clearly separates it from the data-fetching siblings (fetch, get_route, search, etc.), though the resource itself ('capabilities') is implied rather than stated outright.

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?

'before planning' gives real timing guidance for when to call this rather than a data tool, and the closing caution steers how to interpret gaps in results. It does not name an explicit alternative or a when-not-to-use condition, which keeps it short of a 5.

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