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

Annotations already declare destructiveHint=true, so the mutation risk profile is partially covered. The description adds genuinely useful semantics not in the annotations — that unlisted fields are left untouched (a true PATCH, not a replace) — but is silent on permissions/auth requirements, side effects on linked tickets or companies, and reversibility of a destructive update.

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, fully front-loaded: action first, partial-update semantics second, endpoint mapping last. No filler and nothing restated from the title.

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 an 11-param destructive mutation with no output schema, the description covers what it changes, how it changes it, and the underlying API route; annotations cover the destructive classification. Only error behaviour and permission prerequisites are left unspecified, which is a minor gap.

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% across all 11 parameters, so the schema already documents id, name, tags, custom_fields, etc. The description adds nothing parameter-level beyond reaffirming that only supplied fields change, which is the baseline 3 scenario.

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 ('Update fields on an existing contact') and adds a precise scope qualifier that the sibling tools lack. It does not explicitly distinguish itself from freshdesk_create_contact or freshdesk_update_ticket, but the resource/operation pairing is unambiguous.

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 only implied: 'existing contact' signals this is not a create operation, and the partial-update statement tells the caller they need not supply all fields. There is no explicit when-to-use/when-not guidance and no mention of alternatives such as freshdesk_create_contact for new records.

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