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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered. Beyond that the description adds real behavioral facts: locked chats are never returned, list ordering is newest-first, and get returns turns by speaker with start/end seconds plus optional per-word timing. It does not mention paging behavior or what an empty result means.

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-loaded one-line purpose, then a compact action table and four one-line examples. Every sentence carries either a capability, a scope limit, or a usage cue; nothing is padding.

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 9-parameter, 3-action tool with an output schema and full annotations, the description supplies everything an agent needs: action semantics, required inputs per action, return shape, ordering, and the locked-chat exclusion. Return-value details are correctly delegated to the output schema.

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 cross-parameter conditional semantics the per-field schema text only hints at: which filters apply to which action, that search reuses list's filters, and that include_words only affects get. It does not explain target_session, the one parameter that is purely schema-documented.

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+resource (read WhatsApp call recordings and their timed transcripts) and then decomposes the tool into three concretely named actions with distinct outputs. It also distinguishes itself from siblings by naming where recordings link (query, get_contact, get_group), so an agent can place the tool in the graph without opening the schema.

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?

Each action carries its selection condition (list for recent calls, get to read one transcript, search to find matching lines) and four worked examples cover the common cases. It stops short of explicit when-not guidance, e.g. it never says whether to prefer this over query or summarize_conversation for transcript questions.

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