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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint, so the safety profile is fully covered structurally. The description adds only the default window and interval, which arguably belongs to parameters; it says nothing about data freshness, sampling gaps, or behavior when the range is empty. With annotations present, this is adequate but not additive.

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?

Three short sentences: what it returns, why to call it, and the defaults. The purpose is front-loaded and no sentence is filler. Nothing wasted.

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, so the description is the only place a caller could learn what a 'snapshot' looks like (timestamp plus TVL value, per-protocol breakdown?). With 7 parameters and a paginated data-returning tool, that gap is real. The purpose and defaults are covered, but the return shape is not.

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 every parameter including the from/to/period precedence rule is already documented in the schema. The description repeats the default period and interval rather than adding new semantics. Baseline 3 applies since the schema carries the burden.

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?

The description names a specific verb and resource — 'Get historical Total Value Locked snapshots for a yield' — which is unambiguous and distinguishable from siblings like yields_get_risk or yields_get_reward_rate_history. It stops short of explicitly contrasting with those neighbors, but the resource is specific enough that an agent can route correctly.

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?

'Use this to assess protocol health — a declining TVL is a warning sign' gives a rationale for calling the tool, which implies usage. However, there is no explicit when-not guidance, no mention of pairing with yields_get_risk or yields_get_balances, and no statement about what to do when TVL history is unavailable.

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