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

Goes well beyond the annotations: discloses billing behavior (weekly coverage then purchased Credits), that no agent is launched, the optimistic-concurrency requirement that updates/removal need the exact current version, and an explicit prompt-injection caveat that sources/skills are untrusted reference data rather than permission. Some sentences ("skills share this knowledge authority") are cryptic, but the added behavioral context is real.

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 the action and scope, and no sentence is pure filler. However, it compresses billing, agent-launch, concurrency, and security notes into terse, jargon-heavy clauses that are hard to parse on first read.

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?

For a destructive mutation with an output schema, it covers the highest-risk unknowns: authorization scope, cost, concurrency/version precondition, and untrusted-data handling. The gap is the undocumented required and nested parameters, which the description leaves entirely to a zero-coverage schema.

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 0% across 10 parameters (including nested sources and provenance), so the description must carry the load. It explains only two of them — space_id defaulting to Personal and expected_version_id needing the exact current version — and says nothing about idempotency_key, kind, path, title, text, sources, or provenance semantics.

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 and resource ("Update entries in one currently authorized private Space") plus the default scope (Personal). An agent can distinguish it from create/remove/get siblings by name, though the description never names those alternatives explicitly.

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?

Useful scope guidance is present — which Space, and the Personal default when space_id is omitted. But there is no routing guidance versus private_knowledge_create, private_knowledge_remove, or private_knowledge_get/history (which the agent needs to obtain expected_version_id), so the when-to-use picture is only implied.

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