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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed world), so the bar is lower. The description adds real behavioral context the annotations cannot: verified listings rank first and carry the full profile, and it distinguishes the two returned URL fields (listingUrl as the directory source vs url as the product site). It does not state pagination or result-count behavior beyond the schema's limit, so it stops short of a 5.

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 verb and resource come first, then the trigger example, then optional filters, then return semantics. Every sentence carries information, though the middle clause packs three filters into one run-on sentence.

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 compensates by naming the returned fields (listingUrl, url), their meaning, the ranking of verified listings and the profile depth they carry. Combined with the fully documented schema, an agent has everything needed to call and interpret this tool.

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 the baseline is 3. The description still adds meaning beyond the schema: it points category at list_categories as the slug source, notes that child categories are implied, and gives a concrete pricing example ('free' for free tools) plus the ranking effect of matching words.

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 (find/search), the resource (software, SaaS, AI tools and websites listed in this directory) and the matching fields (title, tagline, description, category). It is clearly distinguishable from browse_category, get_listing and find_alternatives, which are named or implied as different entry points.

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 explicit trigger conditions ('use it when a user asks for a tool that does X') with concrete examples, and routes to alternatives: list_categories for slugs and get_listing for the full profile. Exclusions are implied through those hand-offs, leaving little to infer.

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