Update Facebook Page Cover Photo

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

Annotations already indicate the tool is not read-only (readOnlyHint=false), not destructive (destructiveHint=false), and idempotent (idempotentHint=true). The description adds limited behavioral context beyond the schema, such as the permission requirement and the mutual exclusivity of cover_url and photo_id. It does not describe side effects or additional behavior, but the annotations cover the safety profile adequately.

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?

The description is extremely concise: a one-sentence purpose, a structured list of parameters with clear types and descriptions, and a final usage note. No redundant information. The essential information is front-loaded and easy to parse.

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?

Given 6 parameters with 1 required and no output schema, the description adequately covers input semantics and usage. However, it does not describe the return value or success/failure indicators. For a mutation tool, this omission leaves the agent guessing about the response format, which could hinder correct invocation handling.

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?

The description adds meaning beyond the schema by clarifying the page_id parameter (which lacks a schema description) as 'Facebook Page ID' and by explicitly stating the constraint 'Provide either cover_url or photo_id'. This helps the agent understand parameter relationships. With 83% schema coverage, the description compensates for the missing page_id description.

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 title and description clearly state the tool updates a Facebook Page's cover photo. It distinguishes itself from the sibling meta_update_page_picture (which updates the profile picture) by specifying 'cover photo'. The description also notes the requirement to provide either cover_url or photo_id, reinforcing the specific action.

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?

The description explicitly states the required permission ('pages_manage_metadata') and the constraint that either cover_url or photo_id must be provided. However, it does not mention when not to use this tool or provide alternatives, such as using meta_update_page_picture for profile photos.

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