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

Annotations already declare readOnlyHint and idempotentHint, and the description adds valuable behavior beyond that: the per-call cost ($0.001 USDC or 1000 drops XRP), the matched=false no-hit behavior, and explicit confirmation that it is read-only and does not execute code. No contradiction with annotations.

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?

Three dense sentences, each earning its place: purpose, usage and fallback, then exclusions and cost. It front-loads the core action and packs sibling routing near the top without 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?

Given the output schema already handles return values, the description covers everything else an agent needs: when to use, what it does, the no-match fallback, exclusions, cost, and read-only nature. Combined with the annotations and schema, no necessary context 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?

Schema description coverage is 100%, with both parameters already well-documented: 'Raw traceback or exception text' for error_log and 'the library that threw the error' for framework. The description slightly reinforces these meanings but introduces no new semantic detail, so the baseline of 3 is appropriate.

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 states a specific verb and resource: 'Match a stack trace or exception against known deprecated APIs for langchain, llamaindex, ollama, or xrpl and return the replacement plus a fix.' It clearly differentiates from siblings by explicitly excluding happy-path syntax via fetch_latest_syntax and directing to search_ai_framework_docs for no match.

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 when-to-use guidance: 'Use only when you have an error_log.' It also gives a concrete alternative for the no-match case, telling the agent to search_ai_framework_docs with the failing symbol, and states when not to use it ('Not for happy-path syntax'), naming the correct sibling.

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