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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so safety is covered. The description adds real behavioral context beyond that: it discloses the field set returned (compensating for the absent output schema) and notes the unexpected transport, "POST policies/detail," which tells the agent a read is performed via POST. It does not state behavior for a nonexistent or unauthorized policy id.

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 fragments, resource front-loaded, with zero filler. The field enumeration and the API endpoint note both earn their place given no output schema exists, though the telegraphic style is slightly harder to parse than a full sentence.

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 one-parameter read tool with annotations covering the safety profile, the definition supplies the essential missing pieces: the returned field set and the underlying endpoint. Only not-found behavior and where to source a policy_id are unaddressed, which are minor gaps.

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% for the single policy_id parameter, so the description carries the burden. "By id" conveys only that the argument identifies the policy; it adds no format, source (where to obtain a policy_id), or error semantics beyond that. Partial compensation for the coverage gap, so a middle score.

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+resource (get one policy) and scopes it to a single record by id, which distinguishes it from list/search siblings. It enumerates the returned fields (holder, agent, carrier, status, dates, premium, coverages, custom fields) so the agent knows exactly what payload to expect, though it never names search_policies as the alternative.

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?

"One policy by id" implies you must already have a policy_id, which is minimal usage context. There is no explicit when-to-use, when-not-to-use, or routing guidance toward agencybloc_search_policies or agencybloc_update_policy, all of which are plausible alternatives.

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