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

With no annotations, the description carries the full burden and does so: it discloses single-use semantics ('can be fetched only once'), code normalization, the deliberate indistinguishability of unknown/already-fetched/expired failures (a security property), and the verbatim-and-complete return obligation. This is behavioral context an agent could not infer from the schema.

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 core action and the code format, then layers failure modes and the channel-link exception. Every sentence carries distinct operational content; none is filler or restatement of the title.

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?

There is no output schema, and the description compensates by specifying the return contract: content on success, null plus a reason on failure, and the specific channel_code reason. Nothing an agent needs to call or interpret the result 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 code parameter is already documented, but the description adds real meaning beyond it: case-insensitivity, hyphen stripping, the worked example pair, and the fact that a full handover.tools URL is acceptable input. It stops short of describing any other accepted input forms.

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 ('Fetch content stored by handoff_put') and ties it directly to the sibling that produces the input. An agent can immediately distinguish it from handoff_put, handoff_revoke, and the channel_* tools.

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?

Explicitly names the producer (handoff_put) as the precondition, and states the negative case: a channel link must be joined with the channel client, not fetched here. It also tells the agent what happens if the wrong kind of code is passed (reason channel_code with steps).

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