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

The description discloses behavior beyond the annotations: it states cost/free, pure CPU, no network, and read-only at the very front. It also explains the regex-based matching behavior for configText ('marked as looks present or check needed based on simple regex signals'). This adds meaningful context that the readOnlyHint alone does not provide, such as the lack of network dependency and the heuristic nature of the analysis.

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 front-loaded with the cost/read-only note, then immediately states the purpose, followed by usage and pairing. Every sentence carries value: the cost bracket, the topic list, the configText behavior, the use case, and the sibling tool pointers. No fluff or redundant repetition of schema or annotations.

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 three optional parameters and no output schema, the description covers the primary use cases and clarifies how configText alters results. It does not specify the exact output format or what happens when neither vendor nor configText is supplied, but that is inferable (a generic checklist). The mention of specific SIP/WebRTC domains and the 'Pair with' recommendations make it sufficiently complete for an agent to select and use the tool 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?

The schema already provides 100% coverage with detailed parameter descriptions (e.g., configText: 'When supplied, items with matching signals are marked as present'; vendor: 'Omit and supply configText to auto-detect'). The description adds little beyond the schema—only restating the regex-signal idea that is already in the schema. Since schema coverage is high, the baseline is 3, and there is no additional semantic enrichment to justify a higher score.

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 begins with 'Return a curated checklist of WebRTC ↔ SIP requirements' followed by a specific list of items (WSS transport, ICE gathering, DTLS-SRTP, etc.). This clearly states the verb, resource, and scope, and distinguishes it from sibling tools like parse_sdp or review_sip_config by focusing on the WebRTC-to-SIP bridge checklist.

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?

Provides explicit usage guidance: 'Use when the user is building a WebRTC ↔ SIP bridge or troubleshooting one (no media, one-way audio, ICE failures).' Also names specific alternatives and companions in 'Pair with: review_sip_config for the full structured outline; search_sip_docs... parse_sdp / compare_sdp_offer_answer...' This goes beyond implied usage and gives clear when/where-to-use versus other tools.

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