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

Adds substantial context beyond the annotations: reads are synchronous, writes wait per site under Approvals grouped into one approvable run via approve_url, an automatic backup runs beforehand (backup_first, default true) via SiteVault/UpdraftPlus, the change cannot be undone, and the result cannot be verified. This is exactly the behavioral disclosure an agent needs for a fan-out mutation tool.

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?

Dense but front-loaded: the core action and scope come first, then read/write behavior, then return shape. Nearly every sentence carries distinct information; it is long but appropriate for the tool's complexity, with only minor redundancy.

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?

Although there is no output schema, the description specifies the per-site return states (ran, waiting with execution_id, refused with reason). Combined with the annotation coverage and the approval/backup explanation, an agent has everything needed to decide and invoke correctly.

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?

With 100% schema coverage the baseline is 3, but the description adds real meaning: it shows the tool-name formats accepted (e.g. emcp-tools-update-post or <server>/<tool>), clarifies that args must be identical on every site, and confirms site_ids defaults to every eligible site and backup_first defaults to true.

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 and resource: run one tool of another (non-Royal) MCP server with identical arguments across up to 50 chosen sites. The scope constraint (only where the server offers it and the tool is enabled for its connection) and the exclusion of Royal MCP tools make it immediately distinguishable despite the large sibling set.

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 clear conditions: reads run immediately; changes are queued for approval; only non-deleting/non-overwriting tools may fan out, while others are 'refused here and run one site at a time.' This effectively names the alternative path. It doesn't name a specific sibling tool for the single-site case, which keeps it just below a 5.

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