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

Goes well beyond the annotations: returns once the purge is recorded, each host applies it on the project's next request, purged entries re-render on that request, and it discloses the shared rate limit (10/s, bursts of 100) with RATE_LIMITED plus retryAfterSeconds and no-op-on-refusal behavior. The note that 'repeating a purge purges again' clarifies the idempotentHint nuance without contradicting it (resulting state is the same).

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?

Front-loaded with the action and reach, then modes, then behavior and limits. Dense but every sentence carries information; the multi-clause semicolon sentences are slightly heavy but not wasteful.

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?

No output schema, and the description notes only that it returns once the purge is recorded rather than describing the response shape. Nonetheless it covers the caller's decision-relevant context (modes, exclusivity, deferral to next request, rate limits, errors) thoroughly for a 4-parameter mutation tool.

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?

With 0% schema description coverage, the description carries the load: it defines tags as Cache-Tag header values or Next.js revalidateTag tags (max 128), paths as Next.js revalidatePath-style purges (max 64), and everything as all cached entries of the project. It does not restate the path pattern (must start with /) or tag length limits, so it doesn't fully compensate for the gap.

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 (purges) and precise resource (cached responses and data of a permitted project's apps on every Eurobase app host). No sibling performs cache purging, and the three purge modes are enumerated so an agent can distinguish behavior immediately.

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?

Clearly explains the three mutually exclusive modes (tags, paths, everything) and the constraint that everything cannot be combined with tags or paths. It lacks explicit 'when to choose tags vs paths' guidance or when-not-to-use context, but the mode semantics are strong.

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