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

No annotations are provided, so the description carries the full burden of behavioral disclosure, and it fails. 'Uses the same authorization and validation as website, API and CLI' is a non-actionable assertion that does not say who can call it, what gets mutated, how the required revision field governs concurrency/conflict, or whether the change is reversible.

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?

It is short, but brevity here reflects under-specification rather than conciseness. Both sentences are near-zero-information, so there is no waste to trim but also nothing that earns its place for a 6-parameter mutation tool.

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 mutation tool with 6 required parameters, no annotations, no output schema, and zero schema coverage, the description supplies nothing an agent needs to call it correctly. It is completely inadequate relative to the tool's complexity.

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?

All 6 parameters are required with 0% schema description coverage, so the description must compensate and does not. It mentions no parameter at all. Critical semantics are left unexplained: that 'revision' implies optimistic concurrency (so a stale value fails), and what 'source' and 'eligibility' mean as free-text fields.

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 is essentially a restatement of the tool name ('contacts.update' -> contacts_update), which is a tautology. It never states what is actually updated, what fields are affected, or how this differs from siblings like contacts_suppress, contacts_erase, or contacts_import. The 'SAGOT' prefix carries no meaning for an agent.

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?

There is no guidance on when to use this tool versus alternatives. With siblings such as contacts_erase, contacts_suppress, contacts_import, and contacts_history, the agent has no basis for routing. No exclusions, prerequisites, or context are provided.

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