suppliers_update

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

Annotations already declare a non-destructive, idempotent write in a closed world, so the description's job is mainly the exception surface — and it delivers that by naming name/CUI as ANAF-managed and unmodifiable. It does not disclose partial-update semantics (what happens to omitted fields, and whether passing null clears a value), which matters given most properties are nullable.

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, front-loaded with the action and then the constraint; no filler and no restatement of the name or annotations. The most consequential fact (core data cannot be modified) arrives before any field enumeration.

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?

For a 12-parameter mutation with no output schema, the description covers purpose and the immutability constraint but leaves the partial-update contract and the effect of nulls unstated, which is the main ambiguity an agent would hit. Annotations carry the safety profile, so nothing critical is missing about risk, but the update semantics are underspecified.

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 per-field meaning is already documented; the description groups parameters into contact, address, banking and notes categories, adding a little orientation. It says nothing about the required uuid, the null-versus-omit behavior, or the companyId override, so it only modestly exceeds the schema baseline.

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 specific verb and resource ('Update editable fields of a supplier record') and immediately scopes which fields qualify, so an agent knows this is a mutation on an existing supplier rather than a creation or lookup. It does not name the sibling alternatives (suppliers_create, suppliers_get) it is distinguished from, 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?

Implicit guidance is present: the ANAF-sourced immutability statement tells the agent not to attempt name/CUI changes, which prevents a class of failed calls. However there is no explicit 'use this when…' framing, no prerequisites (permissions, existing supplier UUID), and no routing to siblings for creating or reading suppliers.

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