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

Annotations already declare the tool read-only and idempotent. The description adds two operational facts the annotations lack: no workspace is required and calls are not metered. It also notes that a statement type key returns that type's form, which is non-obvious behavior.

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 sentences, with the purpose front-loaded. Each sentence carries distinct information: purpose and scope, subset selection, the default, and the operational profile.

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 no explanation. For a simple read-only lookup with two optional parameters, the description covers scope, parameter usage, prerequisites and cost.

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%. The description still adds meaning beyond it: statement type keys such as 'checking' or 'invoice' are valid terms and return forms. That clarifies what values terms accepts.

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?

It states a specific verb and resource: it returns the FinStat glossary. It also lists what the vocabulary covers (documents, statements, declarations, charts, statement forms/types, the double-entry equation, interchange formats). That scope sets it apart from guide_canonical_schema and guide_tasks.

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?

It explains how to use the terms parameter: omit it for the full pack, or pass a statement type key to get that type's form. It never says when to call this tool instead of guide_canonical_schema, guide_tasks or get_started, so the reason to choose it has to be inferred.

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