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

Annotations already declare this is read-only, idempotent, and non-destructive, so the safety profile is covered. The description adds real behavioral detail: output is Markdown, a known heading returns just that section, and an unknown section returns the heading list instead of erroring.

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?

Front-loaded with the return contract, followed by the section semantics and the routing hint. Slightly dense in the middle but every clause carries information; no filler.

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?

There is no output schema, but the description specifies what the return contains (fields, series types, limits, examples) and how sectioning affects it, which is everything needed to call and interpret the result.

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% and the single parameter is documented, so baseline would be 3. The description adds meaning beyond the schema by illustrating valid values ('Variables', '2D Series Types'), noting omission returns the whole page, and defining the unknown-section fallback.

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 precise verb+resource (return the reference of the Graph Paper plot document format) and enumerates what the reference contains: fields, series types, limits, and examples. It is readily distinguishable from the write-oriented sibling make_plot_link.

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?

Gives explicit ordering guidance — 'Read it before you write a document for make_plot_link' — and names the downstream sibling that depends on it. It also explains the fallback behavior for an unrecognized section, so the agent knows how to recover rather than guessing.

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