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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered. The description adds cost behavior not present in structured data ('Free') and flags that billing/pricing status is part of the output, which is genuinely additive context for an agent deciding whether to call it.

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 compact sentences with no filler, front-loading the returned content and closing with the call-ordering instruction. Every clause carries distinct 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?

For a zero-parameter discovery tool with no output schema, the description carries the burden of telling the agent what comes back, and it does so by enumerating the content categories. It does not describe the response shape (e.g., the fields around the pricing or billing status), leaving a small gap, but nothing needed to invoke it correctly is missing.

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, so there is nothing for the description to disambiguate and the baseline of 4 applies. The listed content topics serve as an informal description of what the parameterless call returns.

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 ('Get') and resource ('capabilities') and then enumerates the exact content returned: languages, free vs paid operations, input limits, privacy posture, x402 pricing and billing status. This is immediately distinguishable from the sibling code-analysis tools (query_code, find_references, etc.), which deal with source artifacts rather than server metadata.

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 explicit ordering guidance: 'Call first when discovering this server.' This tells the agent exactly when in the workflow to reach for it. It stops short of naming exclusions, but no sibling overlaps this tool's domain, so the omission is minor.

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