list_fonts

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

With no annotations at all, the description carries the full burden, and it does disclose the single most consequential behavioral trait: the return shape changes based on arguments (legacy array with no args vs. fonts plus pagination otherwise). That is real value beyond structured fields. It falls short of a 5 because 'return fonts and pagination' is never explained — no mention of total counts, page size behavior, or that filtering is presumably read-only and side-effect free.

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 short sentences, both doing work, with the core capability front-loaded and the invocation-dependent behavior immediately after. There is no filler, preamble, or repetition of the tool name.

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?

Given five undocumented parameters, no annotations, and no output schema, the description covers the riskiest fact (dual response shape) but leaves material gaps: parameter meanings, matching semantics, and what 'pagination' actually contains. It is enough to attempt a call but not enough to call it confidently or to predict the response structure.

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?

Five parameters with 0% schema description coverage, so the description must compensate and largely does not. It refers vaguely to 'filters' and 'pagination' without mapping them to query, style, family, limit, or offset, and never says whether query/style/family are substring, prefix, or exact matches. An agent can only guess that query/style/family are the filters and limit/offset the pagination.

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: 'Find available font families and exact styles,' which is clearly a lookup of font options. No sibling tool in the list deals with fonts, so there is no ambiguity to dispel, but the description also does not differentiate from anything. Clear, though not maximally sharp about what a 'font family' vs 'exact style' record contains.

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 does give invocation-mode guidance: call with no arguments to get the legacy array, or supply filters/pagination to get the richer response. That is useful implied usage, but there is no statement of when to prefer one mode, no prerequisites, and no alternative tools named. An agent must infer which mode it wants from the response-shape sentence alone.

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