capabilities.tools

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

With no annotations provided, the description carries the full burden. It explains the tool's behavior (responses vary by arguments) but does not disclose side effects, authorization needs, or rate limits. Since it is a read-only discovery tool, the description is adequate but not rich.

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?

The description is a single sentence that efficiently communicates the three modes using semicolons. There is no redundant or extraneous information, making it highly concise and well-structured.

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?

Given the absence of an output schema, the description only vaguely describes return types ('domain map', 'its tools', 'one schema'). More detail on the format of these responses would improve completeness, but the tool's simplicity and context (within a capabilities system) mitigate this 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?

Schema description coverage is 0%, so the description must compensate. It effectively explains how each parameter alters the output: name returns a full schema, domain returns tools in that domain. The schema property titles provide minimal context, but the description adds necessary semantic differentiation.

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 clearly states the tool's purpose: navigating THIS server's tools. It specifically lists three modes (no args, domain, name) and what each returns. This differentiates it from sibling tools like capabilities.domains or capabilities.search, which have distinct roles.

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?

The description provides explicit guidance on when to use each of the three modes: without arguments to get a domain map, with domain to get tools in that domain, with name to get the schema. Although it does not explicitly state when not to use this tool or mention alternatives, the usage is clear and actionable.

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