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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, so the safety profile is covered. The description adds genuinely new behavioral detail: that long instrument books are folded into the maturity wall, that per-section coverage states report completeness, and that matured instruments are hidden unless include_matured is set. It does not mention pagination or auth, hence not 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?

Two sentences, front-loaded with the returned surface before parameters. Dense but every clause carries information; the long enumeration of sections is the only mild redundancy against the later 'coverage states' phrase.

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 carries the burden of describing returns, and it does so by enumerating sections and coverage states. Annotations cover the safety profile and parameters are fully documented in the schema. Only the absence of any return-shape detail (e.g. pagination or error behavior) keeps it from a 5.

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 adds value beyond the schema by explaining the mechanism behind bucket (long instrument books fold into the maturity wall, so bucket expands one slice) and by reinforcing that node_id is the graph node id rather than company_profile's entity_id.

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 names a specific resource ('the debt surface of one company') and enumerates exactly what it returns: registered charges, debt instruments, filed debt position facts, aggregates, maturity wall, and coverage states. This distinguishes it from siblings like company_financials, company_public_funding, and company_profile 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?

It tells the agent where node_id comes from ('the graph node id from search_companies hits') and explicitly warns it is 'Not the entity_id of company_profile', which routes the agent correctly. It also explains when to pass bucket and include_matured. It stops short of stating when to prefer this tool over company_financials or company_public_funding, so it is clear context without explicit alternatives.

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