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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuine value beyond that: it explains that the response carries brandContext semantics (colors/fonts/voice/image rules) and the read-before-write pattern that prevents clobbering rule arrays. It stops short of noting failure modes for a missing feedId, which keeps it below a 5.

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 sentences, both front-loaded with action and rationale. The parenthetical listing brandContext contents is compressed but earns its place by telling the agent what it can extract without a second call.

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?

No output schema exists, so the description carries the burden of describing returns, and it names the key fields it yields. It does not describe the overall record shape or what a nonexistent feed returns, but for a single-param read tool it is nearly complete.

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?

There is one parameter with 100% schema description coverage ('12-char nanoid'), so the schema fully carries parameter meaning and the description adds nothing about feedId. Baseline 3 applies.

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 ('Returns the full feed record') and enumerates the payload fields (filterRules, fieldRules, outputSchema, brandContext, plan state), which clearly separates it from list_feeds and get_template without opening either 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 explicit ordering instructions: read this BEFORE designing a template and BEFORE update_field_rules / update_filter_rules, naming the sibling tools and the reason (append/modify the existing rule array without clobbering). No inference left to the agent.

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