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

The description is genuinely informative about consequences ('Deleting takes it off every file (a field's values go with it)') and about cost ('$0.001 per call; nothing if it fails'). However, that disclosed irreversible data loss conflicts with the annotation destructiveHint=false, so the agent gets contradictory safety signals from the two sources.

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, front-loaded with the core operation and kind enumeration, then semantics, then cost. Every parenthetical (field types, yes/no, CRM linkage) carries information the schema does not, so nothing is padding.

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 and sparse annotations, the description carries the burden well: it covers mutation semantics, deletion effects, matching rules, field typing and billing. It does not say what the call returns (e.g. the created definition's identifier) or whether name collisions create duplicates, which is the only real remaining gap for an 8-parameter mutation tool.

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 only 13%, but the description compensates for nearly every parameter: it defines the four kind values, explains case-insensitive name matching, describes delete semantics, states that currency applies to money fields, describes model field_type values (text, number, money, date, boolean, url), and explains correspondent company_id/contact_id. Only new_name is left to inference, and 'rename' supplies it.

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 opens with a precise verb set (add, rename, delete) plus the resource ('one of the account's own ways to file things') and enumerates the four kinds it governs, so the agent knows exactly what class of object is touched. It does not name or contrast against the nearest sibling (files_definitions), which keeps it short of a 5.

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?

Usage is implied by the enumerated operations: create, rename (new_name) and delete (delete) a filing definition, and matching is explicitly case-insensitive by name. There is no explicit 'when to use this vs files_definitions' or 'when not to use' guidance, and no note that listing existing definitions is a different tool, so the agent must infer the boundary.

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