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

Beyond the readOnly/idempotent/non-destructive annotations, the description discloses the compression magnitude, the 100% preservation guarantee, a 32 KB call size and 60 RPM rate limit, payment options (?demo=true or L402 at 50 sats), and the HTTP 400 failure mode. This is substantial behavioral context the annotations do not carry.

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 usage and alternatives, then operational constraints. Every clause carries information, though the final sentence is densely packed with limits and auth details. Efficient and well-ordered overall.

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?

An output schema exists, so return values need not be described. The description covers purpose, sibling routing, resource limits, authentication, and error behavior, leaving no material gap for correct invocation.

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 parameters are fully documented in structured data and the baseline is 3. The description only restates 'content' and alludes to enum defaults without adding semantics the schema lacks. No compensation is required, but no value is added either.

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 (compresses) and resource (source files, logs, transcripts) with a concrete outcome (50–80% reduction while preserving signatures, imports, error frames). It explicitly distinguishes itself from the sibling plan_context_token_budget, which does token counting without altering text. An agent can identify the tool's function 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?

Gives an explicit when-to-use condition ('shrinking oversized source files or logs before feeding them into an LLM prompt') and names the alternative with the contrasting condition (counting BPE tokens/costs without altering text). Nothing is left to inference.

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