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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered by structured data. The description adds that the payload includes capabilities, actions, invariants and pricing, which hints at scope, but says nothing about size, caching, or whether the content is stable across calls — and an output schema already documents the return shape.

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 no filler, front-loaded with the verb and the enumerated payload. It is perhaps overly compressed — 'fleet-standard' is jargon that carries meaning only to someone already familiar with the system — but nothing is wasted.

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 zero-parameter read tool with an output schema and full annotation coverage, the description only needs to convey its role in the workflow, and it does not. It never explains that this is the discovery entry point relative to solve/verify_audit, leaving the agent to infer when to call it.

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?

The tool takes zero parameters and the schema is empty, so there is nothing for the description to disambiguate. Baseline 4 applies; the description correctly implies no arguments are needed.

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 ('Return') and enumerates the content returned: capabilities, actions, invariants, and pricing. Combined with the name describe_agent and the title 'Describe this service', an agent can tell this is the introspection/metadata tool rather than an execution tool like solve or audit_job. It stops short of a full sibling differentiation, but the resource is unambiguous.

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?

There is no when-to-use guidance at all: nothing says whether this should be called before solve or verify_audit to discover available actions, or whether it is optional context-gathering. The alternatives are never mentioned despite five siblings in the same fleet.

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