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

Annotations already declare readOnlyHint=false, destructiveHint=true, idempotentHint=false, and openWorldHint=true, so the safety profile is covered. The description contributes one genuinely non-redundant fact — the master API key requirement — but says nothing about what the destructive update replaces, whether omitted fields are cleared or preserved, or PUT replace-vs-merge semantics.

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?

The prose is two short, front-loaded sentences with no filler. The injected pricing HTML comment block is noise, but the authored content itself is tight and not padded.

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 an output schema present, return values need not be explained, and all parameters are documented in the schema. However, for a 13-parameter destructive mutation with destructiveHint=true and idempotentHint=false, the description omits partial-vs-full update semantics and any effect of the call, leaving the definition only minimally viable.

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 13 parameters, so the schema already carries the semantics and the baseline of 3 applies. The description adds no parameter-level meaning (e.g., that only the required id is needed and the rest are optional fields to change), leaving it purely a restatement.

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 states a specific verb and resource ("Update call records"), which is marginally more informative than the name alone, but it adds no detail beyond the title "Update Call Records" and does not distinguish this mutation endpoint from siblings such as post_apollo_phone_calls or get_apollo_phone_calls_search. It is clear but generic.

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 when-to-use guidance, no mention of alternatives (e.g., post_apollo_phone_calls for creation), and no exclusions. "Requires a master API key" is a prerequisite, not usage guidance, so the agent gets no routing help.

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