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

Annotations only declare a non-read-only, non-destructive write. The description adds genuine behavioral context beyond that: links pointing at the old './slug.html' across every page are rewritten to follow the new slug, and the home page's reserved 'index' slug is locked while its display name remains editable. It does not cover failure modes (e.g. collisions with reserved names) or what the response returns.

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 short sentences, front-loaded with the core operation, then the side effect, then the edge case. Nothing is wasted and no sentence is merely restating the schema.

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 three-parameter mutation with no output schema, this covers the target selection, the two mutable fields, the cross-page consequence and the one hard constraint (locked index slug). Missing only error/permission behavior and confirmation of how the new slug is reported back.

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%, so the schema already explains name, page and the fileName slug format including folder paths and sanitization/dedup. The description reinforces that both name and slug are optional-ish targets ('and/or') but adds no syntax or format detail beyond the schema, so the baseline 3 applies.

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 (rename) and resource (page) plus the secondary slug change, and maps itself to a known UI affordance ('the Pages panel's rename'). It is easily distinguishable from create_page, delete_page, duplicate_page and rename_site in the sibling list.

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?

Usage is clear from the phrasing: it is the tool for changing an existing page's name or URL, and the reader is pointed to list_pages via the schema for obtaining the page identifier. It does not name an explicit alternative or call out when not to use it, so it stops short of a 5.

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