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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds useful context beyond these: the operation is 'PUBLIC,' has 'Risk R0,' and carries no commercial obligation, plus canonical single-entry semantics.

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 short sentences with no filler. The core action and identifier options are front-loaded, and the risk/public classification is appended compactly.

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 single-parameter lookup with strong safety annotations, the description is essentially complete: it states the input identifier types and the read-only nature. It does not specify return shape, but title implies a description and annotations cover safety.

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 coverage is 0%, so the description carries the full burden for the 'entry' parameter. It compensates by explaining that the value may be a slug, capability id, or stable directory id, which is meaningful guidance the schema itself does not provide.

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?

Description uses a specific verb ('Read') with a specific resource ('one canonical directory entry') and names three identifier types, making it distinct from sibling search tools like search_directory. It clearly states the tool's singular, canonical lookup scope.

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?

Implied usage is clear: call this when you have a slug, capability id, or stable directory id and need the canonical entry. It does not explicitly name alternatives or state when not to use it, but the identifier-based, single-entry wording provides enough routing context.

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