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

Annotations already declare readOnly, idempotent, non-destructive, and not open-world, so the safety profile is covered. The description adds behavioral context beyond that: the per-page character cap, that page count is returned, and that the document must be shared with the workspace. It does not discuss errors or rate limits, but the additions are substantive.

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?

Three dense sentences, front-loaded with the operation and its size cap, followed by usage and the sibling alternative. No filler or restatement 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?

An output schema exists, so return values need no explanation, and the description still supplies the character cap, page-count behavior, id provenance, and the routing to search_docs. Nothing needed to invoke 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 coverage is 100% and the page parameter already documents its 1-based default, so the schema carries the parameter burden. The description echoes the single-page/character-cap semantics and flags that documentId comes from list_documents, adding marginal but not decisive value beyond the schema.

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 (read) and resource (one page of a shared document) plus the scope cap (up to 24,000 characters) and that page count is returned. The description immediately distinguishes this from search_docs and from the generic Twelfth-help sibling.

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?

Explicitly says when to use it ('when the answer is in a shared sheet or doc'), where to obtain the required id ('from list_documents (or a project's documents in get_project)'), and names the alternative for a different need ('to find how Twelfth itself works use search_docs instead').

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