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

The description adds context beyond annotations: 'Safe, read-only local filesystem scan. Makes no network calls and modifies no files.' This specifies the scan scope (local filesystem) and network behavior, which annotations do not cover. Given that annotations already declare readOnlyHint, idempotentHint, and destructiveHint, the added detail is useful but not extensive; a 4 is appropriate.

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 well-organized with sections for usage and behavior, but it is slightly verbose—'Safe, read-only local filesystem scan. Makes no network calls and modifies no files.' could be condensed. The primary purpose is front-loaded in the first sentence, and the structure is logical, earning a 4.

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 tool with a single simple parameter and no output schema, the description covers the core functionality, usage, and behavior comprehensively. It lists the types of information discovered (frameworks, routing, sitemap/robots, page inventory), which is sufficient for an agent to invoke it correctly. No critical information is missing.

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 input schema already documents the single parameter (projectPath) with full 100% coverage, including default and example. The description does not add any parameter-specific meaning, so the baseline of 3 applies since the schema handles the burden.

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 clearly states a specific verb ('Discovers') and a concrete resource: website architecture, frameworks, routing, sitemap/robots, and page inventory. It distinguishes itself from sibling tools by specifying it operates on a local codebase, which is a clear differentiator.

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?

Explicit usage guidance is provided: 'Use when starting an audit of a local codebase' and 'Do NOT use for remote websites or live URLs; use 'seo_crawl_and_extract' or 'seo_audit_sitemap_multipage' instead.' This names alternatives and conditions, leaving no ambiguity.

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