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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds genuine behavioral context beyond that: the return shape ('report-style data grouped by account') and the default date window ('last 90 days if no date range provided'). It stops short of pagination/volume caveats, but the additions are real.

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?

Four tight sentences with no filler, front-loaded with purpose, then return shape, then default behavior, then the disambiguation hint. Every sentence carries information an agent needs.

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 read-only search tool with no output schema, the description covers purpose, return grouping, default date semantics, and sibling disambiguation, while annotations carry the safety profile. Nothing required to call it correctly is missing.

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 100%, so parameter documentation already lives in the schema (baseline 3). The description adds the implicit defaulting behavior for dateFrom/dateTo that the schema does not state, which is meaningful semantics beyond the structured fields.

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 ('Search accounting ledger transactions for a company') and immediately differentiates itself from the closely-named sibling 'search-transactions'. An agent can distinguish the two 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?

Explicitly names the alternative ('Use search-transactions instead when you need transaction IDs for commenting'), giving a concrete condition that selects between the two near-identical tools. This is exactly the when-to-use-this-vs-alternative guidance the dimension asks for.

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