List document fonts

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

No annotations are provided, so the description carries the full burden. It discloses the scope ('source-embedded') and the return fields, which is useful. However, it does not explicitly state that the operation is read-only, nor does it describe error handling, performance, or whether it accepts only certain formats. The format list in the description also conflicts with the broader format enum in the schema, creating ambiguity.

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?

The description is a single, well-structured sentence that front-loads the primary action ('Lists every source-embedded font face') and includes essential scope and return-value details. Every word earns its place, with no redundant phrasing.

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 simple read-only listing tool with one parameter, the description is largely sufficient: it explains the purpose, supported document formats, and the kind of data returned. The lack of an output schema is partially compensated by listing the fields (family, weight/style, byte length). However, it does not explicitly state the return structure (e.g., array of objects) or behavior when no fonts are embedded, and the format mismatch with the schema leaves a 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?

The schema already provides 100% coverage of the 'source' parameter with detailed descriptions for both path and bytesBase64+format branches. The tool description adds no extra parameter-level detail beyond the schema. However, the description's format list (docx/pptx/odt/odp/ods/odg) is narrower than the schema's format enum (which includes xlsx, odf, markdown, pdf), potentially confusing an agent about which formats are actually supported.

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?

The description clearly states what the tool does: 'Lists every source-embedded font face' from supported document formats, and specifies the output fields (family, weight/style, byte length). This is a specific verb+resource combination that distinguishes it from sibling tools like describe_font_file, which likely describes font files rather than fonts inside documents.

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 description implies when to use the tool (when you need to know embedded fonts in a document) but does not explicitly mention alternatives or when not to use it. Sibling tools like describe_font_file exist, but no cross-references are given, so usage guidance is only implied rather than stated.

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