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

Goes well beyond the annotations: discloses that captions can be silently dropped, that Method requires an assignee on standard accounts, that the reply re-reads the activity so links can be verified, and that no email is sent. These are non-obvious server-side behaviors an agent would otherwise only discover by failing.

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?

Front-loads the mutating nature with 'WRITE:' and then packs id resolution, the caption pitfall, auth requirement, return behavior, and side effects into dense, non-redundant sentences. No 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?

With 8 parameters, no output schema, and no enums, the description compensates fully: it identifies required inputs, explains id lookup, warns about the silent-drop trap, and describes the response ('re-reads the activity'). Nothing needed to invoke it correctly is missing.

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 the baseline is 3, but the description adds real cross-field meaning: contact_id is the Contact's RecordID 'not the Customer's', the note body goes in Comments, and activity_type_id should be preferred over activity_type. It does not cover due, status_id, or assigned_to_id beyond what the schema says.

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?

Opens with 'WRITE: logs an activity (call, email, to-do, note) on a customer/lead', giving a specific verb, resource, and enumerated subtypes. An agent can immediately separate it from siblings like method_list_activities and the generic method_create_record.

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 actionable routing advice: prefer activity_type_id over the caption because 'a caption that matches zero or several options is silently dropped', and points to method_list_contacts and method_get_table_fields for resolving ids. It doesn't explicitly say when to use this versus method_create_record, but the context is otherwise clear.

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