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

Annotations already declare read-only, idempotent, and closed-world behavior. The description adds meaningful context beyond them: it returns the diagram, its loops, changes since the last call, an edit link, and a prompt-injection warning that diagram text is data, not instructions.

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 compact and front-loaded: purpose first, then when to use it, then what it returns, then the safety note. Every sentence adds useful information without repetition or 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?

For a simple one-parameter read tool with no output schema, the description covers input formats, usage contexts, returned content, change tracking, and the key prompt-injection safety concern. Nothing essential for calling or interpreting the tool 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 coverage for the single `diagram` parameter is 0%, so the description must compensate. It does so by explaining that the parameter accepts either an id or a pasted site link in the form `.../d/{id}`, though it does not mention the 200-character limit or finer id syntax.

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 states a specific verb and resource: read the latest version of a diagram by id or pasted site link. It is clearly distinct from create_diagram and edit_diagram in practical use, though it does not explicitly name or contrast those siblings.

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 gives explicit usage contexts: bringing a diagram into a conversation, or when the person says they changed it on the site. It does not state when not to use it or explicitly route to create_diagram or edit_diagram for other scenarios.

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