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

Goes well beyond the readOnlyHint=false / destructiveHint=false annotations: confirms appends never conflict, that sequence numbers are gapless, and gives the 25-entry batch cap plus a 64 KB body ceiling. The idempotency replay behavior in the retry window is spelled out with the exact error code. It does not state whether a batch is atomic on partial failure, which is the main remaining behavioral gap for a mutable tool.

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?

Two tight sentences: the mechanical contract first, the intended use case second. Every clause carries information — limits, conflict behavior, sequencing, entry shape — with no repetition 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?

An output schema exists, so return values need no explanation, and the description covers the write semantics, limits and idempotency an agent needs to call it correctly. Missing: whether an oversized or partially failing batch rolls back, and what doc_key/namespace resolve to.

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 only 25% and the entries array is an untyped object bag, so the description carries real weight by naming the per-entry fields body, frontmatter and idempotency_key and the size limit on body. idempotency_key is also fully documented in-schema. doc_key and namespace still get no explanation in either place, so it compensates but not completely.

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 (append) and resource (entries to a log document), including the batch cap of 25. The clause 'No expected_version and never a version conflict' implicitly separates it from optimistic-concurrency writers like upsert_shared_doc or patch_doc_section, and 'gapless seq' pins the log semantics that distinguish it from read_entries.

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 logs for progress notes, messages and discussions' gives positive usage context but never names an alternative tool. With siblings like send_message, write_continuation, upsert_many and read_entries in the catalog, an agent gets no explicit rule for choosing append_entries over them or for when not to use it.

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