VisiMark function reference

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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds the non-obvious trait 'Reads no file,' signaling this is a pure in-memory reference lookup rather than a file-consuming operation like eval/check, and it discloses the shape of the returned content. Useful context beyond the safety annotations.

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 tight sentences, front-loaded with the returned content and followed by the invocation modes. No filler; every clause carries information.

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?

With no output schema, the description compensates by listing what a lookup returns (signature, arity, precision, errors, examples), and the readOnly annotations cover the safety profile. The only gap is sibling differentiation, which is not strictly required for correct invocation.

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% and the single `name` parameter is fully documented as an example (`SUM`) with the omit behavior. The description restates 'omit `name` for the whole reference' without adding new semantics, so the schema is doing the heavy lifting and the baseline 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?

States a specific verb (look up) and resource (builtin functions) and enumerates what the entry contains: signature, arity, precision, errors and examples. It does not, however, differentiate itself from siblings like visimark_explain or visimark_check, which plausibly overlap with 'explain a function'.

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 explains the two invocation modes (pass `name` to look up one builtin, omit it for the whole reference), which is genuinely operative guidance. It never states when to prefer this tool over visimark_explain or visimark_check, so the routing decision is left implicit.

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