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

Annotations cover the safety profile (readOnlyHint, idempotentHint, openWorldHint=false), and the description adds substantial context beyond that: red/blue flagging with ↑/↓, US vs SI ranges overridable per value, a plain-text companion version for notes, a link-based delivery model where data rides in the URL, and a privacy warning never to include patient identifiers. It also discloses the "drawing aid, not clinical decision support" framing and the Edit-link adjustability. This is rich, non-redundant behavioral disclosure.

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?

It is a single dense paragraph, front-loaded with purpose, then features, routing, and constraints — a sensible order. It runs long and repeats the "drawing aid, not clinical decision support" line already present in the schema description, but nearly every sentence carries actionable information for the caller.

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 generate-an-image tool with a rich input schema and no output schema, the description covers what matters: what gets produced, that a link (not inline image) is the deliverable, that a plain-text version is included, flagging behavior, and privacy constraints. Nothing an agent needs in order to call it correctly 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%, so the schema already documents every parameter thoroughly, and the description's parameter notes (values as strings up to 8 characters, 1–8 panels) largely restate the schema. It does add some framing by describing the fishbone layout per panel type, but with the schema doing the heavy lifting a baseline 3 is appropriate.

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 opens with a specific verb+resource: "Generate clean lab fishbone diagrams (lab value skeletons)", then enumerates the exact skeletons (BMP/Chem-7, CBC, coags, LFT, ABG, Ca/Mg/Phos) and their layouts. It explicitly distinguishes itself from the sibling create_fishbone (Ishikawa cause-and-effect diagram), so an agent can tell them apart without opening either schema.

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 states the selection condition plainly ("Choose it whenever lab results should be shown in fishbone form") and names the alternative and its exclusion ("not a cause-and-effect (Ishikawa) diagram, for which use create_fishbone"). It also gives operational guidance — infer missing details rather than asking, and always surface the image link — leaving little to inference.

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