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

Adds substantial behavior beyond the read-only/idempotent annotations: each call consumes prepaid credits regardless of result count, credentials are held by Aether so the agent never sees URL or token, confirm_charge=false yields a dry-run quote, and a wrong ticker guess spends credits on the wrong endpoint. These are exactly the cost and side-effect disclosures an agent needs.

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?

Four sentences, front-loaded with the core action, and every sentence carries operational load (cost model, credential model, routing rule, prerequisite). Some issuer guidance overlaps the schema description but the redundant phrasing reinforces the credit-loss risk rather than wasting space.

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?

An output schema exists, so return values need not be explained, and the description covers everything else: prerequisites, cost model, credential handling, dry-run mode, and routing behavior. For a 7-parameter, credit-spending, open-world tool this is complete.

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 71%, and the description fills in the semantics that matter most: why issuer/ticker routing is preferred over query-text detection, that empty partners means no fan-out and no charges, and the legacy nature of ticker_filter. `query` and `limit` remain undescribed in both places, keeping this short of a 5.

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 concrete verb and resource: 'Route the agent's query server-to-server to one or more seller-registered API endpoints.' This is specific and actionable. However, it never contrasts itself with the closely named sibling partner_search, leaving the agent to infer which of the two routing tools to use.

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 an explicit prerequisite ('Use list_partners first to discover available endpoints and per-call credit costs') and a conditional routing rule ('Pass `issuer` when the question is about one company'). It also warns that partners must be chosen explicitly to avoid surprise charges. Missing an explicit when-NOT-to-use-this / partner_search distinction, so not a 5.

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