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

Annotations already cover read-only, idempotent, non-destructive, but the description adds genuinely new behavior: only the last 50 distinct errors are kept, messages have credentials redacted, no request data is stored, and capture_enabled reflects whether recording is on. That is substantive context beyond the structured fields, though it does not discuss latency or failure modes.

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 return shape is front-loaded and the sentences are dense with facts rather than filler. Minor waste in the trailing '(site: ...)' and 'Through Royally: read-only, runs straight away', which restate the annotations and schema-supplied site.

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 no output schema, the description fully carries the burden by enumerating every returned field (message, file, line, plugin_slug/theme_slug, count, first_seen, last_seen) plus capture_enabled and the paused-plugin list. Combined with the permission requirement and retention limit, an agent has everything needed to call and interpret it.

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 limit and since are already documented in the schema, and the description only indirectly explains the 50-error cap behind the limit parameter. It adds no semantics for 'since' or the site_id enum, so the baseline of 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?

The description names the specific resource (PHP fatal errors recorded on the site) and adds a second result class (plugins/themes WordPress paused after a fatal error), which an agent could not infer from the tool name alone. It does not explicitly distinguish itself from the closest sibling, wp_get_error_log_tail, though the parenthetical 'with or without the debug log' hints at the difference.

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 context is implied rather than stated: the tool is for diagnosing fatals and pauses, and 'Requires manage_options' gives a real precondition. There is no explicit when-not guidance and no named alternative for the raw-log case, so an agent must infer which sibling to pick.

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