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

Annotations already establish the safe-read profile (readOnly, non-destructive, closed-world), and the description adds substantive behavior beyond that: it enumerates the reply contents (page code, shared code, element ids, the currently selected element). This tells the agent exactly what it will receive, which annotations cannot.

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 core action and the freshness constraint before the when-to-use clause and the return-value detail. Slightly long with three stacked clauses, but each carries information rather than padding.

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, so the description must cover return values, and it does so fully (page code, shared code, element ids, selected element). Combined with the annotations' safety profile, an agent has everything needed to call this correctly 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 67%, with page and with_shared documented in the schema and deck_id undocumented. The description doesn't add format or semantics for any parameter, though its mention of 'the code every page shares' loosely contextualizes with_shared. Baseline 3 is appropriate where the schema does most of the work.

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 design) and qualifies the scope sharply: 'as it is NOW — the code the person's editor shows, including their own edits.' This freshness framing implicitly separates it from a brief-style sibling like get_page_brief, but no sibling is named, so it stops short of a 5.

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?

'Use it whenever the person asks to change something in a design that already exists' gives an explicit trigger condition and the rationale ('their editor may hold edits you have not seen'). It stops short of naming when-not-to-use or naming the alternative (get_page_brief / edit_page) directly, so it is clear context without exclusions.

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