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

Annotations already establish the safe-read profile (readOnlyHint=true, destructiveHint=false), so the bar is lower. The description nonetheless adds real behavioral value: 'Reading never activates a company' pre-empts a plausible side-effect fear, and it explains the null case (existing pricing contract, billing unchanged), which is not derivable from annotations or schema.

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 core purpose, then states, then the null caveat, then when-to-use and an example. Every sentence carries information, though the sentences are dense and the null clause is a slight interruption to the primary flow.

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-value explanation is not strictly required, yet the description still summarizes the returned quote, capacity, approval flag and blockers. Combined with the read-only annotations, an agent has everything needed to call it correctly; only the sibling-routing gap 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 description coverage is 100% and the single `account_id` parameter is fully documented in the schema, including its provenance ('from a previous read or search_records'). The description adds no parameter detail beyond that, so the baseline 3 applies.

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 specific verb and resource ('Review a company's billing state') and enumerates the states it can report (free prospect, paid active, free archived), so the agent knows exactly what it returns. It does not, however, explicitly differentiate itself from the sibling `manage_company_billing`, which is the nearest alternative an agent might confuse it with.

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 an explicit 'When to use' trigger ('Before activating or archiving a company') plus a concrete example ('What would activating this company cost?'). It gives clear positive context but names no alternatives or when-not-to-use conditions, so it stops short of routing guidance.

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