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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description still adds non-obvious context: reference data, nothing account-specific, needs no sign-in, contacts no business, and that it is safe to call once per session rather than repeatedly. It stops short of describing freshness/staleness of the pricing card, which would be the remaining behavioral unknown.

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?

Front-loaded with the purpose and the contents of the card, with the sibling exclusions and the trigger example at the end where they belong. Slightly dense — the long enumerated return list plus the 'changes nothing' restatement of destructiveHint could be trimmed — but nearly every clause carries information.

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?

There is no output schema, so the description compensates by naming the returned fields (pricing card, live_skills shape, mcp_url, gate_mcp_url, quickstart_url, docs_url, connect_steps). Combined with the auth/side-effect disclosure and the call-timing example, an agent has everything needed to invoke it 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?

Zero parameters, so the baseline is a 4, and the description confirms it explicitly with 'takes no arguments', removing any doubt about whether filters or identifiers are required. No further parameter meaning is possible.

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?

Specific verb+resource: 'Read the OdileM2M network card for Direct,' followed by an enumeration of exactly what the card contains (live skills, credit costs, packs, limits, Gate MCP address, quickstart). It explicitly positions itself against two named siblings, so an agent can distinguish it without opening any schema.

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?

States the use case ('cost Direct tasks before sending any'), the exclusions with named alternatives (get_agent_services for product choice, get_direct_usage for own balance), and a concrete trigger ('call it once with no arguments before the first send_to_business of a session'). Nothing is left to inference.

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