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

With no annotations, the description carries the burden well: it discloses field immutability, the permission model, and that scope_note is subcontractor-visible ('what they see on their page'). It stops short of stating update semantics for the nullable, all-optional fields — whether passing null clears a value or leaves it unchanged.

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 short sentences: what changes, the immutability/alternative rule, then the permission gate. Mutable surface is front-loaded and no sentence is filler.

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 no explanation, and the safety/permission picture is covered. The one real gap for a partial-update tool with nullable optional fields is whether omitting or nulling a field clears it.

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 0%, so the description must explain the parameters, and it gives real meaning to three of four: contact_name, trade, and scope_note as the subcontractor-facing note. subcontractor_id is only implied by the tool topic, and null/omission semantics for the optional fields remain unspecified.

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 (change) and the exact mutable fields (contact name, trade, scope note) on a named resource (subcontractor). It also carves out what is NOT mutable (email and link), which lets an agent distinguish this from subs_add without opening the 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?

Gives an explicit when-not rule with the alternative workflow: 'The email and link never change; remove and add again for a new person.' It also states the required actor ('Owner or office only'), so the agent knows when the call will be rejected.

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