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

Annotations already cover idempotency, non-destructiveness, and closed-world scope, so the bar is lowered, yet the description still adds real behavior: a lost stage requires lost_reason from the org's list, the pipeline follows the stage, owner_id must be a person of this team, and empty signatory values clear the field. It does not disclose error behavior or response shape, but that is a minor gap against the annotation coverage.

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 tool's core action is front-loaded correctly, but the body is one long, dash-heavy paragraph mixing field lists, stage rules, and identity constraints. Every clause carries information, yet the run-on structure makes it harder to scan than a short bulleted grouping would.

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 16-parameter mutation tool with no output schema and 50% schema coverage, the description supplies the missing rules on conditional parameters (lost_reason, pipeline_id), identity constraints, and clearing semantics. Remaining gaps are the already-documented simple fields and any post-update return expectations.

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?

With 16 parameters and only 50% schema description coverage, the description compensates meaningfully: it explains presales_channel values as a channel-of-contact note, presales_handle as the address on that channel, lost_reason's dependency on the org's list, owner_id's team constraint, and pipeline_id's role as a consistency check. Several params (title, amount, currency, contact_id, signatory fields) are still named without added semantics, which keeps this below 5.

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 a deal's fields...') and enumerates exactly which fields are in scope, including the presales sub-group. It also differentiates behaviorally from siblings move_deal (stage-change rules) and write_to_a_tommo_on_a_deal ('Tommo never writes to presales; the rep does'), so an agent can place it 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?

Usage is implied rather than stated: the move_deal rules reference signals relevance for stage changes, and the presales clause signals what the tool does not do. There is no explicit when-to-use guidance vs update_contact, create_deal, or move_deal for a given rep intent, and no prerequisites (permissions, id validity) are spelled out.

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