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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, closed-world, so the safety profile carries no burden on the description. The description still adds real value by disclosing the pagination contract (one page per call) and the upstream API surface. It says nothing about default page size, ordering, or auth requirements, which keeps it at adequate rather than 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?

Three short sentences, front-loaded with the purpose before the endpoint and pagination notes. The bare API URL is slightly dead weight but also a legitimate pointer for edge cases. Nothing is padded.

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?

An output schema exists, so return values need not be described, and the tool has zero required parameters, lowering risk. The description covers the two things an agent most needs to know beyond the schema: paging behavior and the aggregate alternative. Missing a note on how page/limit/offset combine, which is the main remaining 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?

With 9 optional parameters and 67% schema description coverage, the schema does most of the work, so 3 is the baseline. The description only elaborates on one nested parameter (summarize.all_pages) and its role in cross-page totals; the other eight, including page/limit/offset interplay, get no additional meaning from the prose.

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 and resource ("Retrieve a list of tax reductions") and pins it to a concrete upstream endpoint (GET /3/taxreductions), so there is no ambiguity about what is returned. It does not need sibling differentiation because no other tool in the list touches tax reductions, but the phrasing largely echoes the title.

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 page per call; use summarize.all_pages for totals over every page" gives an explicit routing rule: single-page reads here, aggregate totals via the summarize parameter. That is a genuine alternative-path instruction rather than a vague hint. It stops short of saying when this tool is not appropriate (e.g. when to prefer a filtered or single-record lookup).

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