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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, non-destructive), so the lower bar applies. The description adds genuinely useful behavior: it explains the tool is documentation about 'which tools to use for what' and that omitting the topic switches it into a listing mode, which is a mode-change not implied by readOnlyHint alone.

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 front-loaded sentences with no filler; the action and scope come first, then the prerequisite, then the enumeration trick. The mid-sentence list of subject areas is long but earns its place by hinting at valid topic strings, so it is slightly wordy rather than wasteful.

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 read-only documentation tool with no output schema and one optional parameter, the description supplies everything needed: what it returns (guide content for an area), why to call it (before writing in that area), and how to enumerate valid inputs. No meaningful gap remains.

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 optional parameter already documents its purpose with example values. The description reinforces the area-based topic concept but adds no naming syntax, format, or case rules beyond the schema's examples, so the baseline 3 is correct.

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 (a page of the ScreenWeaver guide) and enumerates the subject areas covered (script, story elements, storyboard, production canvas, art direction, references, credits). No sibling among the 22 tools offers documentation, so the agent can partition this tool from the CRUD/project tools immediately.

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 an explicit trigger: 'Read the page for an area before your first write there,' which is a concrete precondition for calling other tools. It also explains the discovery path ('Call with no topic to list the topics'), so the agent knows how to bootstrap when it doesn't know valid topics.

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