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

Annotations only cover readOnlyHint and openWorldHint; the description goes well beyond them by disclosing the three-tier resolution strategy (index, then Envelop history API, then log scan) and the fact that the response reports which source served the request and how current it is. That fallback and provenance behavior is exactly the kind of trait an agent cannot infer from the schema or annotations.

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?

A single sentence front-loads the resource and what is returned, then appends the data-source behavior. It is dense but every clause carries information; no filler. A slight split into two sentences would read more cleanly.

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 no output schema, the description must carry return-value context, and it does list the returned fields (open time, pool, lifetime fees, events) plus the source-provenance note. It omits details like pagination or ordering for the all-positions case, which is a minor gap for a read-only lookup.

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 semantic value: salt is described as selecting the single-position mode versus the all-positions listing for a manager, which the schema's terse 'Position key' label does not convey. chainId and manager semantics are already fully documented in the schema.

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?

Names a specific verb and resource (retrieve every position of a manager, or one position by salt) and enumerates the payload fields: open time, pool, lifetime fees, events. The sibling tools (list_operators, rank_pools, suggest_move) are unrelated operations, so no sibling disambiguation is needed and none is missing.

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: pass manager alone for all positions, add salt for a single one. There is no explicit when-to-use vs. alternative guidance and no stated prerequisites (e.g. whether the manager must be indexed), but the two invocation modes are discernible from the description.

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