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

Annotations already establish the safe read-only, idempotent profile, so the bar is lower; the description adds substantial value by enumerating the extra fields returned (issuance costs by participant, call dates, credit enhancement, ADTR rows), which no annotation conveys. It does not address lookup failure behavior or rate limits, keeping it out of the top tier.

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?

Purpose and keying identifier are front-loaded, and every listed field earns its place by telling the agent why to reach for this tool over search. It is, however, a single very long run-on sentence with a dense list, which slightly hurts scanability.

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?

With no output schema, the description carries the return-value burden and does so thoroughly, enumerating the additional cost and structure fields. Combined with annotations covering the safety profile, an agent has everything needed to call it correctly.

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 100%, so the schema already documents cdiac_number with an example and the accepted digit-only/spaced forms. The description only adds that it is 'the YYYY-NNNN identifier CDIAC assigns each issue', which largely restates the schema, so the baseline 3 applies.

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 (retrieve full detail), a precise resource (one California municipal bond issuance), and the keying identifier (CDIAC number). It explicitly positions itself against the sibling search tool ('everything the search tool summarises plus'), so an agent can distinguish it from ca_debt_search_issues without opening either schema.

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 phrase 'everything the search tool summarises plus...' clearly frames this as the drill-down reached after identifying a specific issue, distinguishing it from the search sibling. It stops short of an explicit when-not or a named alternative, but the usage context is unambiguous.

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