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

Annotations already declare readOnlyHint=true and destructiveHint=false; the description reinforces this with 'Writes nothing.' It adds valuable behavioral detail on how matching works: exact amount requirement and ranking by date proximity and description. This goes beyond the structured annotations without contradicting them.

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 sentences, front-loaded with the core purpose, followed by ranking logic and side-effect guidance. Every clause adds information; there is no filler or repetition.

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?

Complete for a read-only suggestion tool: purpose, matching criteria, side-effect profile, and the next-step sibling are all covered. The output schema handles return-value details, so nothing needed for invocation or correct use 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 description coverage is 100%, with both parameters fully labeled as UUID value wrappers. The description does not add extra parameter-level context, but the schema already carries the burden, so the baseline score of 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?

Description states a specific verb ('Rank') with a clear resource ('ledger transactions against a statement's unmatched lines') and defines the tool's exact job. It differentiates from the sibling confirm tool by explicitly saying it does not write and that confirmation happens elsewhere.

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?

Description tells the agent when to use it: to rank candidates against unmatched lines before applying a match. It explicitly names the alternative follow-up tool, accounting_confirm_statement_match, and warns that this tool writes nothing, which prevents misuse.

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