update_progress

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

With zero annotations, the description carries the full load and does so richly: monotonic-only semantics with explicit rejection of lower values plus the error returning the current value, idempotency via absolute values, and retry safety. These are exactly the non-obvious behaviors an agent needs.

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 with purpose, then the critical monotonic constraint in bold, then idempotency, then the operational recommendation. Every sentence carries distinct information with no redundancy.

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 an 8-param, no-annotation, no-output-schema mutation tool, the description covers the crucial behavioral contract (monotonicity, rejection, idempotency, stalling). It doesn't describe the return payload beyond the rejection case, but the schema fully documents the remaining parameters, so coverage is nearly complete.

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%, so the baseline is 3, but the description adds real meaning beyond the field docs by clarifying that current is absolute rather than a delta and drawing the idempotency consequence. That is a semantic contribution the schema does not spell out.

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 (推进进度字段) and scopes it to long-running tasks, with the parenthetical (长耗时任务用) routing the agent away from the general update_task sibling. An agent can identify the operation and its domain 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?

Clearly states when to use it (long-running tasks) and adds an operational directive (report periodically) tied to a concrete consequence (being flagged by list_stalled). It stops short of explicitly naming update_task or get_task as alternatives, so it's clear context but not full when/when-not/alternative routing.

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