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

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: omitted keys (None) preserve current values, while empty string or clear_*=True wipes a slot — exactly the destructive nuance an agent needs. It stops short of noting permission requirements or validation.

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 summary followed by a compact Args block; every sentence earns its place. There is mild redundancy between the summary sentence about omitted keys and the per-param notes, but it is not 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?

With an output schema present, return values need no explanation, and the destructive/mutation behavior is fully spelled out. Missing only peripheral context such as whether a rebuild/publish is required for changes to take effect.

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 0%, so the description carries the full burden, and it does: every one of the 7 params (project_id, header, body_code, footer, clear_body, clear_header, clear_footer) is documented with its exact semantics, including the None-keeps/""-clears contract.

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 gives a specific verb+resource with scope: updating custom code (header, body, footer) for a project. It does not, however, distinguish itself from the sibling get_custom_code (the read counterpart), so the agent gets no explicit routing help.

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 states a validation constraint (at least one of header/body_code/footer/clear_* must be supplied), which implies how to invoke it, but it never says when to reach for this tool versus get_custom_code for reading or update_page for other page edits. Usage is implied rather than directed.

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