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

The description goes well beyond the readOnly/idempotent annotations by revealing append-only semantics, the refusal to calculate performance from commitments, the absence of fabricated historical backfill, and the boundary that paid current signal data is not exposed. These are meaningful behavioral traits an agent needs to set expectations correctly.

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 description is front-loaded with a 'Use when' trigger, then packs precise, non-redundant details about return contents and behavioral guarantees. The final disclaimer is short and earns its place by preventing misuse. No sentence is 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?

Given the two optional parameters, an output schema, and read-only annotations, the description is complete: it explains what is returned, what is intentionally not computed, the ledger's history boundary, and how to decide when to call it. Nothing critical for correct invocation or expectation-setting 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 description coverage is 100%, so the schema already documents 'limit' and 'since_as_of' with clear meanings. The description adds context about manifests and the ledger but does not directly elaborate on parameter usage, which matches the baseline of 3 for high schema coverage.

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 opens with a specific set of user intents ('what Hesper Atlas actually published, when it was committed, what changed, or whether forward history is mature enough to evaluate') and then names the exact deliverable: public append-only manifests for end-of-day signal publications. It also distinguishes itself from sibling signal/list tools by emphasizing that it proves commitments without exposing the paid current signal book.

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?

The description explicitly says 'Use when a user asks...' and lists four concrete triggering conditions, making the appropriate invocation context clear. It does not name alternative sibling tools or state when not to use this tool, so it stops short of a full 5.

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